I wanted to read about diverse perspectives across North America, but found there wasn't any challenge covering the states in Mexico, so I thought I'd add that one! Any books that either take place in, stop in, or talk about the state counts. Mexican territories are optional prompts. The challenge gives you a few years, in case you're juggling other challenges.

Many books with a setting in Mexico do not explicitly say which state or town they happen in, and some books use a fictional town for the setting, so use your best judgement or Google to find a state that matches what is described in the book.